How to put data line by line into a vector - c++

Question

I want to read a text file line by line (I do not have many integers in each line). I want to sort each line and put them into a vector of a vector. The problem is I cannot insert them into vector line by line. I cannot let them stop at the end of the line. This is what I have now. Can anyone help me?
For example, my text file like this:
1 5 3 7 29 17
2 6 9 3 10
3 89 54 67 34
I want my output like this:
1: 1 3 5 7 17 29
2: 2 3 6 9 10
3: 3 34 54 67 89
vector<int> v;
vector<vector<int>> G_AL;
if(line!=0){ // Build matrics
string lines;
while (getline(fin, lines)) {
istringstream os(lines);
float temp;
while(os >> temp ) {
if(temp != '\n') {
v.push_back(temp);
sort(v.begin(), v.end());
// get v
}
else
{
}
G_AL.push_back(v);
}
}
}

Answer 1

Try this:
std::stringstream fin("2 1 3\n4 6 5\n10 9 7 8"); // Test data
std::vector<std::vector<int>> G_AL;
std::string lines;
while (getline(fin, lines)) {
std::istringstream os(lines);
std::vector<int> v;
float temp;
while(os >> temp)
v.push_back(temp);
sort(v.begin(), v.end());
G_AL.push_back(v);
}
for (size_t i=0; i<G_AL.size(); ++i)
{
std::cout << i+1 << ": ";
for (auto const & v : G_AL[i])
std::cout << v << " ";
std::cout << std::endl;
}
There are some problems in the code you provided:
The v vector is declared outside of the loop, so the values keeps accumulating every line since v is not cleared. Declaring it inside the loop fixes the problem and avoid having to clear it.
The sort can be done only once we finished reading the line.
You push the v vector into G_AL after ever value instead of after every line.
You compare a float with a character (\n), which doesn't work. In fact, the line os >> temp will evaluate to false if there is no floating point value to read, so there is no need to test once more for the end of the stream.